Reports of black flies in surrounding area

EDITOR’S NOTE: The following column was submitted by the Garland County Extension Service, University of Arkansas Division of Agriculture Research & Extension.

Black flies are very small flies that have a distinctive hump behind their head. The common name for these flies is Buffalo gnats (because of their hump) or turkey gnats. They are found in many areas of the United States including areas of Arkansas.

Buffalo gnats need moving water for their lifecycle. The female flies attach several hundred eggs (150-800) to submerged objects such as plants, rocks and leaves. The time frame for the eggs to hatch is dependent on the water temperature with the eggs hatching in 4-5 days at 70 degrees Fahrenheit. The larvae then attach themselves to submerged objects, such as plants or rocks, and filter feed on bacteria and algae in the water. The development time of the larvae also depends on several factors, such as water temperature and available food. These larvae mature and spin a cocoon to pupate in; from which, the adults emerge in the late spring. Adult males and female blackflies feed on nectar. However, females of most species also need blood to produce eggs. The females immediately search for a meal of blood and can travel more than 10 miles to obtain one. The entire life cycle takes about 4-6 weeks, depending on the species of black fly, temperature, available food and water temperature. It is possible for several generations to be produced each year. Fortunately, the adults only live 2-3 weeks.

The bites of the buffalo gnat can be very painful and itchy, and some people and animals may have an allergic reaction to the anticoagulant injected by the fly at the bite. The adult females feed on the blood of many animals including: horses, cattle, sheep, goats, poultry and humans. The bites are usually

concentrated around the head on the ears, nose and face. However, they will bite any exposed area.

In addition to the blood loss, the flies can cause severe irritation to the animals, causing them to continually seek areas to avoid being bitten. Buffalo gnats do have a preference of one host over another, hence one of the common names of turkey gnat.

Large concentrations of the gnats can cause death in animals and poultry due to blood loss, irritation, shock and suffocation. Poultry that have been bitten by buffalo gnats usually have small scabbed cuts on the face and combs or there may be blood stained feathers on the head, neck and wings.

Some birds may be found dead with no apparent lesions; however, a closer examination usually reveals the very small gnats in the feathers covering the ear or on the head. The face and comb of the bird may also be swollen due to large numbers of bites.

Animals such as horses and cattle usually have swollen ears and small scabbed over cuts on the ears. Often these cuts will ooze blood for some time.

Buffalo gnats feed in the daytime, so the best method of protection is avoidance. Livestock and poultry should be sheltered during the daytime in darker areas to lessen the chance of being bitten.

The gnats prefer to feed when there is little, if any, wind. So the use of fans to circulate the air where the animals are kept may be helpful.

Insecticides containing permethrin compounds can be used for temporary reduction of buffalo gnat numbers; however, these products only kill the flies they contact and as such animal areas, yards and barns need to be sprayed periodically.

Some poultry owners use citronella oil containing compounds on their birds with some success. Other methods of prevention used by poultry owners include hanging fly strips or shiny aluminum pie plates that have been coated with a light coating of oil in the sunlight. The black flies rest on the yellow fly strips or coated pie plates and become stuck. It is important to check your poultry periodically, especially those that may be caged in areas where they get lots of sunlight. If suspicious lesions are observed on the birds, they appear restless, egg production has dropped, you notice small amounts of blood on the birds or other animals, or there are unexplained deaths, you may have a buffalo gnat problem.

Since people can also be bitten by buffalo gnats, it is important to protect yourself. If you have to be outside when the gnats are active, wear long-sleeved bright colored clothing. Insect repellents that contain DEET may also be helpful.

Individuals that get bitten and have an allergic reaction should seek prompt medical attention.

Fortunately, in Arkansas, the time for adult black fly activity is short and declines when temperatures get above 80 F.

For additional information on Buffalo gnats or for more information on poultry diseases, care and husbandry, call Jimmy Driggers, county Extension agent – staff chair, Garland County Cooperative Extension Service, 623-6841, or email jdriggers@ uaex.edu.